Background: Electrodiagnostic (EDX) testing, including electromyography (EMG) and nerve conduction studies (NCS) can provide invaluable information to ensure correct diagnosis of a variety of musculoskeletal and neurologic complaints. Therapy guided by such a diagnostic evaluation can improve the function and quality of life for veterans with such common conditions as carpal tunnel syndrome (CTS) and lumbosacral radiculopathy (LSR), while avoiding unnecessary and potentially dangerous surgery for persons with similar complaints with other etiologies. Past VHA experience with quality improvement efforts such as the National Surgical Quality Improvement Project has demonstrated that high quality, validated, clinical data is necessary (though not sufficient) to motivate active participation among clinicians. Objectives: Our previous work suggests that use of EDX procedures varies widely across VISNs in VHA, analogous to the marked geographic variation in provision of EDX by specific provider types that we found in our earlier study of private sector data. Moreover, we have found that EDX encounters at low volume facilities and those performed by non-physician providers are less likely to adhere to evidence based national guidelines published by the American Association of Electrodiagnostic Medicine (AAEM). This suggests that there may be important opportunities for improving the quality of EDX services in VHA. We have designed this pilot project with two short term objectives, which are essential to our long-term research agenda of improving the quality of EDX services provided within VHA. First, we intend to validate our administrative data algorithm for determining the indication for EDX testing, and for determining whether that testing adheres to authoritative guidelines. Second, we will identify and characterize the most common patterns of deviation from guidelines. Methods: Using our established administrative data algorithms, we will identify all persons who have had an EDX encounter during fiscal year 2009, characterize their indication for the procedure and determine if the testing adhered to guidelines. Using VistaWeb, we will review the electronic medical record (EMR) for a sample of these encounters. We will select our sample to ensure adequate numbers of persons in important subgroups defined by facility volume, provider type, and indication. Using the EMR, we will determine the indication for the procedure and whether the EDX encounter adhered to national guidelines. This EMR review will be carried out by trained abstractors under close supervision by physicians with experience requesting and performing EDX studies. During the analysis phase, we will characterize the accuracy of our administrative data algorithm for determining indication and adherence using chart review as the gold standard. We will compare the accuracy of the algorithms between subgroups of particular interest - for example, those defined by provider type and facility volume. Finally, we will identify common patterns of non-adherence using each of the encounters we find to be non-adherent on chart review. Relevance to veterans healthcare: EDX testing is a high volume, costly procedure that can have important benefits for veterans health. However, it is complex and highly dependent on operator skill and knowledge. It is essential that we accurately characterize the quality of current VHA practice and develop methods to ensure the quality with which this important healthcare procedure is delivered.